Island Climate Update 38 - November 2003

23 March 2007 - 2:22pm

Science Centres: Pacific Rim

November

Monthly climate

ENSO & SST

Forecast validation

Three-month outlook

Feature article

Data sources

Feature article
Slightly Higher Risk of Tropical Cyclones for South Pacific Countries near the Date Line Dr Jim Salinger, Dr Jim Renwick and Stuart Burgess For some South Pacific countries near the Date Line the chances of tropical cyclone activity are slightly higher than normal for the November 2003 – April 2004 season. The last few tropical cyclone seasons were relatively ‘quiet’ except last year, with only six occurrences during 2000/01, five in 2001/02, but increasing to ten last season (near the long-term average).

Forecast validation
Forecast validation Forecast period: August to October 2003 Average or above average rainfall was expected from Papua New Guinea east to Tokelau, including Samoa, with above average rainfall forecast for Tokelau and Tuvalu. Average or below average rainfall was expected from Western Kiribati east-southeast to the Marquesas Islands, with below average totals in Eastern Kiribati. Another large region of average or below average rainfall was expected from Vanuatu to the Society Islands, including the Southern Cook Islands, Fiji, Tonga and Niue.

ENSO & SST
ENSO and Sea Surface Temperatures Tropical Pacific in a neutral ENSO state Equatorial SSTs warmed slightly The tropical Pacific remains essentially in a neutral state with no change in the ENSO indices from last month. Equatorial SST anomalies have risen a little recently, and westerly zonal wind anomalies were evident across the western Equatorial Pacific. The NINO3 SST anomaly rose slightly to about +0.7°C in October (from +0.3°C in September). NINO4 rose to +0.9°C (from +0.7°C in September).

Monthly climate
Climate developments in October 2003 Below average rainfall over much of the Southwest Pacifc Above average rainfall over parts of Vanuatu and New Caledonia A region of suppressed convection and generally below average rainfall moved west during October to encompass the Caroline Islands, Nauru, and southern parts of Western Kiribati. Another region of reduced convection moved east, situated over Fiji and Samoa. It was very dry, with 50% or less of average rainfall in parts of Western Kiribati and Fiji.

November
An overview of the present climate in the tropical South Pacific Islands, with an outlook for the coming months, to assist in dissemination of climate information in the Pacific region. Number 38 – 8 November 2003 October’s climate: Rainfall was below average over much of the Southwest Pacific from the Caroline Islands to Eastern Kiribati, and from the region east of Vanuatu to Samoa, including Fiji.

Three-month outlook
Rainfall outlook for November 2003 to January 2004 Enhanced convection in Papua New Guinea, the Solomon Islands and Samoa Average or above average rainfall in parts of French Polynesia Average or below average rainfall about the Date Line from Vanuatu to Niue Below average rainfall in Eastern Kiribati and the Marquesas Islands Enhanced convection in the equatorial western Pacific is likely to result in average or above average rainfall in areas from Papua New Guinea east to the Solomon Islands and Samoa.

Data sources
Sources of South Pacific rainfall data This bulletin is a multi-national project with important collaboration from the following Pacific nations: American Samoa Australia Cook Islands Fiji French Polynesia Kiribati New Caledonia New Zealand Niue Papua New Guinea Pitcairn Island Samoa Solomon Islands Tokelau Tonga Tuvalu Vanuatu Requests for Pacific island climate data should be directed to the Meteorological Services concerned. Acknowledgements This bulletin is made possible with financial support from the New Zealand Agency for International Development (NZAID), Wellington, New Zealand, wi